Monday, April 11, 2011

Pet owners recently browsing the Internet may have gotten the impression that cuddling with Rover could cause mortal danger: “Letting Sleeping Dogs Lie in Your Bed Can Kill You” and “Sleeping with Pets Brings Risk of Serious Disease” are just two examples of sensationalized headlines splashed around the web. “I knew it was going to be controversial, but it’s my job as a public health researcher to warn people about the risks,” said Bruno Chomel, a veterinary zoonoses expert at the University of California-Davis and co-author of the paper that caused all the fuss.

Many of those scare headlines, however, missed the main point of Chomel’s work: For most people, the risks are minimal, and there are easy ways to go about preventing pet-to-owner disease sharing.

While cat-napping with kitties or stealing a kiss with puppies, pet owners can expose themselves to a whole cornucopia of nasty ailments — from plague to parasites, rabies to Chagas disease — according to the article that appeared January in the journal Emerging Infectious Diseases. An estimated 62 percent of American households have pets, researchers say; that adds up to 60 million dogs and 75 million cats. Of these, approximately 27 percent of dogs and 60 percent of cats have “conquered our bedrooms.” At first glance, the potential for a mass epidemic instigated by our furry friends seems like a real-life Hollywood nightmare scenario. But before bullying your pet with a harsh “Get off the bed, I mean it this time!” as one hysterical news story suggests, take a step back. First consider whether your pet could even be guilty of the disease charges, since some are so rare that they exclude the vast majority of pets.

First, there’s plague. That’s right, plague: the infamous Black Death of fourteenth century Europe that claimed about 75 million lives. As any high school student knows, plague is transmitted from the bites of infected fleas that normally live on rats. What most people do not know, though, is that plague can still be found in rodent populations in the western United States, like Colorado, New Mexico, and Arizona. Although rats are the fleas’ preferred hosts, when plague begins to decimate rodent populations, fleas will settle for a substitute mammal host. This is where the cats and dogs come into play, explains Kevin Griffith, a medical epidemiologist at the Centers for Disease Control and Prevention.

Plague-carrying fleas prefer rodents and are not happy feeding on cats and dogs, Griffith says, so when a pet brings a plague-carrying flea into a home, the fleas tend to be mobile, abandoning the pet in search of their preferred host. If owners are spending six to eight hours sleeping with a pet, this gives the fleas an opportunity to move and potentially infect the other occupant of the bed.

Griffith reports that only about seven cases of plague have occurred per year between 2005 to 2010, making it a rare disease that most people don’t have to worry about. This is roughly equivalent to the chance of getting struck and killed by lightening. In contrast, about 850 people die per year from intestinal infections caused by Escherichia coli in undercooked hamburgers or salmonella in runny eggs. And if you live on the East Coast, none of this even applies since plague-carrying fleas don’t live there. For those who reside in the Western United States, though, it seems owning pets could put them more at risk. Interviews with nine people who contracted the disease revealed that eight of them had dogs, and of those eight, four slept with their animals, Griffith says.